Loading apparatus and system for expandable intraluminal medical devices

ABSTRACT

Medical device loading apparatuses, systems, methods and kits are described. A loading apparatus comprises a main body having a proximal end defining a proximal opening, a distal end defining a distal opening, and a passageway extending between the proximal and distal openings. The passageway defines a proximal chamber having a first inner diameter, a distal chamber having a second inner diameter, and a transition chamber disposed between the proximal and distal chambers. The transition chamber has an inner diameter that transitions from the larger second inner diameter to the smaller first inner diameter. The main body has a separable connection that divides the main body between proximal and distal portions when disrupted. An expandable intraluminal medical device can be loaded into a delivery catheter using the loading apparatus by placing the device into the passageway such that it is in a radially-expanded configuration; pulling the device along an axial path through the loading apparatus such that the device transitions from the radially-expanded configuration to a radially-compressed configuration; and pushing the radially-compressed device along the axial path into the delivery catheter.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/061,980, filed on Oct. 24, 2013, which is a continuation of U.S.application Ser. No. 12/860,422, filed on Aug. 20, 2010, now U.S. Pat.No. 8,585,019, which claims priority to U.S. Provisional Application No.61/235,402, filed on Aug. 20, 2009. Each of these related applicationsis hereby incorporated by reference into this disclosure in itsentirety.

FIELD

The disclosure relates generally to the field of expandable intraluminalmedical devices. More particularly, the disclosure relates to the fieldof expandable intraluminal medical devices that are loaded into adelivery device, such as a percutaneous delivery catheter, prior todeployment at a treatment site. Apparatuses and systems for loadingexpandable intraluminal medical devices, such as stents, includingcoronary and other stents, stent graft devices, and prosthetic valves,such as prosthetic heart valves and prosthetic venous valves, into adelivery device are described. Related kits and methods are alsodescribed.

BACKGROUND

A variety of expandable intraluminal medical devices have been developedover recent years. Stents, for example, are routinely used in severalbody lumens as a means for providing support to ailing vessels, such ascoronary and non-coronary vessels. Stent-graft devices are frequentlyused to provide support from within a body vessel and/or to exclude aportion of a vessel wall from the lumen of the vessel. Prostheticvalves, including heart and venous valve devices, that includeexpandable support frames have also been the focus of considerabledevelopment efforts over the last several years.

Irrespective of the ultimate function of the device, expandableintraluminal medical devices are typically delivered to a point oftreatment using a delivery system designed for percutaneous techniques.In a conventional procedure, a caregiver navigates the delivery systemthrough one or more body vessels until the expandable intraluminalmedical device, which is typically contained within a distal tip orportion of the delivery system, is positioned at or near the desiredpoint of treatment. Next, the caregiver deploys the expandableintraluminal medical device from the delivery system, either by removinga constraining force for self-expandable devices or by providing anexpansive force for balloon-expandable devices. Once deployment iscomplete, the delivery system is removed from the body vessel, leavingthe expandable intraluminal medical device at the point of treatment.

During delivery, expandable intraluminal medical devices are maintainedin a reduced-diameter configuration within the delivery system to ensurenavigability of the delivery system through the body vessel. It isnecessary, therefore, to compress the intraluminal medical device andplace it within the delivery system at some time prior to use in thetreatment procedure. For some devices, including some cardiac stents,this loading procedure can be conducted as part of the manufacturingprocess, i.e., prior to shipment to the treatment facility. For otherdevices, however, various concerns caution against loading the device atany time not immediately prior to delivery. For example, sometissue-based devices, such as prosthetic heart and venous valves, mustbe maintained in an appropriate fluid during all storage periods priorto use in a treatment procedure to ensure the integrity of the tissuecomponent of the device. Furthermore, the effects of reduced-diameterstorage of such tissue-based devices, particularly long-term storage,are not well-characterized and, as a result, are desirably avoided atthis time.

A loading procedure that is conducted immediately prior to treatment issubject to several concerns not considered critical for such proceduresconducted outside of the treatment theater. For example, the loadingprocedure must not require bulky equipment that is difficult to useand/or inappropriate for the treatment theater. The procedure must beefficient and simple, and any materials or devices used in such aprocedure should be easy to handle and operate. A need exists,therefore, for a simple apparatus that facilitates loading of anexpandable intraluminal medical device into a delivery device. A needfor improved methods of loading expandable intraluminal medical devicesinto delivery devices also exists.

BRIEF SUMMARY

Apparatuses for loading expandable intraluminal medical devices into adelivery device are described. An apparatus according to one embodimentcomprises a main body having a proximal end defining a proximal opening,a distal end defining a distal opening, and a passageway extendingbetween the proximal and distal openings. The passageway defines aproximal chamber having a first inner diameter, a distal chamber havinga second inner diameter, and a transition chamber disposed between theproximal and distal chambers. The second inner diameter is greater thanthe first inner diameter and the transition chamber has an innerdiameter that transitions along an axial length of the transitionchamber from the second inner diameter to the first inner diameter. Themain body has a separable connection that divides the main body betweenproximal and distal portions when disrupted.

The separable connection can provide a separating line between theproximal and distal portions that intersects a longitudinal axis of themain body at a point where the inner diameter of the transition chamberis greater than the outer diameter of the distal tip of a deliverydevice intended for use with the loading apparatus.

Systems for loading and delivering expandable intraluminal medicaldevices are also described. A system according to one embodimentcomprises a loading apparatus comprising a main body having a proximalend defining a proximal opening, a distal end defining a distal opening,and a passageway extending between the proximal and distal openings. Thepassageway defines a proximal chamber having a first inner diameter, adistal chamber having a second inner diameter, and a transition chamberdisposed between the proximal and distal chambers. The second innerdiameter is greater than the first inner diameter and the transitionchamber has an inner diameter that transitions along an axial length ofthe transition chamber from the second inner diameter to the first innerdiameter. The main body has a separable connection that divides the mainbody between proximal and distal portions when disrupted. The systemalso includes a delivery catheter comprising an outer tubular memberdefining a sheath lumen, a dilator body disposed within the sheath lumenand defining a dilator lumen, and a distal tip member comprising anelongate cannula and a distal tip. The elongate cannula is adapted to beslideably disposed within the dilator lumen and the distal tip memberdefines an outer diameter that is smaller than at least the second innerdiameter of the main body of the loading apparatus.

A inner sleeve can be included to provide a mechanical lead-in to theproximal chamber of loading apparatus. The inner sleeve preventsengagement between the expandable intraluminal medical device and theleading edge of the outer tubular member of the delivery catheter duringa loading procedure. Alternatively, a circumferential edge that providesa mechanical lead-in to the proximal chamber can be formed on an innersurface of the main body of the loading apparatus.

Kits useful in the loading of an expandable intraluminal medical deviceinto a delivery device are also described. A kit according to oneembodiment comprises a loading apparatus according to an embodiment, anexpandable intraluminal medical device, and a delivery catheter.

Methods of loading expandable intraluminal medical devices into deliverydevices are also described. Exemplary methods include one step ofpulling an expandable intraluminal medical device along an axis so thatit transitions from a radially-expanded configuration to aradially-compressed configuration, and another step of pushing theradially-compressed expandable intraluminal medical device along an axisand into a delivery device.

Additional understanding of the claimed invention can be obtained withreview of the following detailed description and the appended drawings,which illustrate the described exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a loading system according to a firstembodiment.

FIG. 1A is a magnified view of the area indicated in FIG. 1.

FIG. 2 is a sectional view of the loading apparatus of the loadingsystem illustrated in FIG. 1.

FIG. 3 is a perspective view of the inner sleeve of the loading systemillustrated in FIG. 1.

FIG. 4 is a sectional view of a loading apparatus according to analternate embodiment.

FIGS. 5A through 5F illustrate use of the loading system of the firstembodiment.

FIG. 5A is a sectional view of an expandable intraluminal medicaldevice, a loading apparatus, and a delivery catheter during an initialstep of loading the medical device into the delivery catheter.

FIG. 5B is a sectional view of an expandable intraluminal medicaldevice, a loading apparatus, and a delivery catheter during another stepof loading the medical device into the delivery catheter.

FIG. 5C is a sectional view of an expandable intraluminal medicaldevice, a loading apparatus, and a delivery catheter during another stepof loading the medical device into the delivery catheter.

FIG. 5D is a sectional view of an expandable intraluminal medicaldevice, a loading apparatus, and a delivery catheter during another stepof loading the medical device into the delivery catheter.

FIG. 5E is a sectional view of an expandable intraluminal medicaldevice, a loading apparatus, and a delivery catheter during another stepof loading the medical device into the delivery catheter.

FIG. 5F is a sectional view of an expandable intraluminal medicaldevice, a loading apparatus, and a delivery catheter during another stepof loading the medical device into the delivery catheter.

FIG. 6 is an exploded view of a loading system according to a secondembodiment.

FIG. 7 is a schematic of a kit according to a third embodiment.

FIG. 8A is a perspective view of an alternative pull wire structure.

FIG. 8B is a partial perspective view of the alternative pull wirestructure illustrated in FIG. 8A engaging a strut of a support frame ofan expandable intraluminal medical device.

FIG. 8C is a partial perspective view of the alternative pull wirestructure illustrated in FIG. 8A engaging a strut of a support frame ofan expandable intraluminal medical device that includes a graft member.

FIG. 8D is a partial perspective view of two alternative pull wiresengaging struts of a support frame of an expandable intraluminal medicaldevice that includes a graft member.

DETAILED DESCRIPTION

The following detailed description and the appended drawings describeand illustrate various exemplary embodiments. The description anddrawings serve to enable one skilled in the art to make and use theinvention; they are not intended to limit the scope of the invention orthe protection sought in any manner.

As used herein, the term “system” refers to a collection ofinteroperable components, one of which is a loading apparatus inaccordance with an embodiment.

As used herein, the term “loading apparatus” refers to an apparatususeful in the loading of an expandable intraluminal medical device intoa medical device delivery catheter or other apparatus into which suchloading is desired, such as storage vessels, research equipment,sterilization containers, and other suitable apparatuses adapted tocontain an expandable intraluminal medical device in a compressed orreduced-diameter configuration.

FIG. 1 is an exploded view of a system 10 for loading an expandableintraluminal medical device into a delivery catheter. The system 10includes loading apparatus 12, delivery catheter 14, stiffening mandrel16, inner sleeve 18, expandable intraluminal medical device 20, pusher22, and tip member 80. As described below, some of these components areconsidered optional. As will be described in greater detail below, auser can load the expandable intraluminal medical device 20 into thedelivery catheter 14 by advancing a distal portion of the deliverycatheter 14 into a proximal portion of the loading apparatus 12, pullingthe expandable intraluminal medical device 20 proximally to position itwithin the proximal portion of the loading apparatus 12, pushing theexpandable intraluminal medical device 20 proximally to position itwithin the distal end of the delivery catheter 14, and removing thedelivery catheter 14 from the loading apparatus 12. During the loadingprocess, the expandable intraluminal medical device 20 transitions froman expanded configuration to a compressed configuration.

The loading apparatus 12 has a main body 30 with proximal 32 and distal34 ends and a passageway 36 that extends between the ends 32, 34. Theproximal end 32 defines a proximal opening 38 that provides access tothe passageway 36. Similarly, the distal end 34 defines a distal opening40 that provides access to the passageway 36.

The passageway 36 includes a proximal chamber 42, a distal chamber 44,and a transition chamber 46. The proximal chamber 42 has a first innerdiameter 48. The distal chamber 44 has a maximum second inner diameter50 that is larger than the first inner diameter 48. The transitionchamber 46 has a transition inner diameter 52 that varies over thelength of the transition chamber 46 from the second inner diameter 50 tothe first inner diameter 48. As will be described more fully below, thisgradually reducing transition inner diameter 52 of the transitionchamber 46 provides an interior surface that compresses the expandableintraluminal medical device 20 as it is moved along a lengthwise axis ofthe loading apparatus 12 from the distal chamber 44 and into theproximal chamber 42.

As best illustrated in FIG. 1, the distal chamber 44 and transitionchamber 46 can cooperatively define an inner surface that provides thedesired transition from the second inner diameter 50 to the first innerdiameter 48. It is noted, though, that alternative chamber structurescan be used. For example, the transition chamber 46 can be eliminated,leaving only the proximal 42 and distal 44 chambers. In this embodiment,the distal chamber 44 includes a gradually reducing inner diameter thattransitions from a first, relatively large inner diameter to a second,relatively small inner diameter. The second, relatively small innerdiameter is advantageously the same as the first inner diameter 48 ofthe proximal chamber 42. While it can be eliminated, the inclusion of anintermediate transition chamber 46 is considered advantageous at leastbecause it provides a greater axial length over which the expandableintraluminal medical device 20 can be transitioned from itsradially-expanded configuration to its radially-compressedconfiguration. Also alternatively, the distal chamber 44 can include auniform, greater second inner diameter 50. In this embodiment, thelength of the distal chamber 44 can have an axial length that is equalto, substantially equal to, or greater than the axial length of theexpandable intraluminal medical device 20, which allows the device 20 tohave a consistent degree of expansion over its axial length whiledisposed in the distal chamber 44.

The passageway 36 is defined by an inner surface 54 of the main body 30.The main body 30 also includes an outer surface 56. In the illustratedembodiment, the outer surface 56 has a relatively uniform outerdiameter. It is expressly understood, though, that the outer surface 56can have a diameter that varies along the length of the main body 30,such as a diameter that substantially mimics the inner diameter as itvaries along the length of the main body 30 as described above.

The main body 30 includes separable connection 58 that joins proximal 60and distal 62 portions of the main body 30. FIG. 2 illustrates theloading apparatus 12 following separation of the proximal 60 and distal62 portions by operation of the separable connection 58. The innersleeve, which is held captive between the proximal 60 and distal 62portions of the main body 30, is not depicted in FIG. 2 to betterillustrate the structural arrangement of the proximal 60 and distal 62portions. In the illustrated embodiment, the separable connection 58comprises mating threads 58 a, 58 b disposed on the proximal 60 anddistal 62 portions of the main body, respectively. In the illustratedembodiment, an outwardly-facing thread 58 b is disposed on the distalportion 62 and an inwardly-facing thread 58 a is disposed on theproximal portion 60.

While a threaded connection is illustrated for the separable connection58, it is expressly understood that any suitable separable connectioncan be used for joining the proximal 60 and distal 62 portions of themain body 30. A skilled artisan will be able to select an appropriateseparable connection for a loading apparatus according to a particularembodiment based on various considerations, including the material(s)used for the main body 30, the intended user of the loading apparatus12, and the desired ease with which the separable connection 58 shouldbe able to be operated to achieve separation of the proximal 60 anddistal 62 portions. Other examples of suitable separable connectionsinclude magnetic connections, mechanical connections, such as twist andlock-type connections, clamp connections, and the like.

No matter the form and structure of the separable connection, it isconsidered advantageous that the separable connection 58 provide aseparating line 59 between the proximal 60 and distal 62 portions thatlies in a plane that is perpendicular, or substantially perpendicular,to a lengthwise axis of the main body 30. Furthermore, positioning theseparating line 59 provided by the separable connection 58 along thelength of the transition chamber 46 is considered desirable at leastbecause the transition diameter 52 ensures that the distal portion 62 ofthe main body 30 can be passed over the distal tip body 84 of the tipmember 80 following a loading procedure, as will be described more fullybelow. Thus, the inner diameter of the passageway 36 at the separatingline 59 is advantageously greater than the outer diameter of the distaltip body 84 of the tip member 80. Also, as described more fully below,the first inner diameter 48 is also advantageously greater than theouter diameter of the distal tip body 84 of the distal tip member 80. Asused herein, the term “separating line” refers to an interface betweentwo components and includes the opposing surfaces of components that canbe connected via a separable connection, such as the proximal 60 anddistal 62 portions of the main body 30 when these portions are joined atseparable connection 58.

The loading apparatus 12 can be formed of any suitable material, such asglass, plastic, and other suitable materials. A skilled artisan will beable to select an appropriate material based on various considerations,including the nature of the expandable intraluminal medical device 20and any required sterilization processes that must be used. If theexpandable intraluminal medical device 20 includes biological tissuethat must be or may be sterilized, such as by gamma irradiation or othertechniques, an appropriate material able to withstand these processesshould be selected for the loading apparatus 12. Also, materials able towithstand prolonged exposure to storage fluids, including conventionalstorage fluids such as saline, are considered advantageous. For at leastthese reasons, glass and plastic materials are currently preferred forloading apparatuses intended to be used with such intraluminal medicaldevices. While glass is considered an acceptable material, it is lesspreferred than plastic materials because of its tendency to become moretacky following exposure to ethylene oxide during sterilization cycles.Plastic materials are considered particularly advantageous at leastbecause of their ready availability, suitability for machining and otherforming techniques, well-characterized nature, and acceptance in themedical arts.

No matter the material selected, a lubricious coating can be used tofacilitate movement of the expandable intraluminal medical device 20through the passageway 36 of the loading apparatus 12 during a loadingprocedure. For example, the inner surface 54 of the loading apparatus 12can be coated with a suitable lubricious coating known in the medicaldevice art. The inventors have determined that a coating layer ofparylene-C on the inner surface 54 reduces the force needed to move anintraluminal medical device from the distal chamber 44 and into theproximal chamber 42, as compared to the force needed to accomplish thesame movement in a loading apparatus 12 with an uncoated inner surface54. In one test, a pull force of 5-10 lbf was required for an uncoatedmain body, while a pull force of <3 lbf was required for a parylene-Ccoated main body. A coating that provides different and/or additionalbenefits can also be applied to the inner surface 54. For example, acoating that protects the material of the main body 30 from anychemicals used in the fabrication of the intraluminal medical device 20may be advantageous.

A guide tube 64 is disposed through the passageway 36. As described morefully below, the guide tube 64 is, before a loading procedure isinitiated, disposed in or inserted in the passageway 36. The guide tube64 advantageously has a length that allows it to extend through at leastthe axial length of the proximal chamber 42 and into the lumen definedby the expandable intraluminal medical device 20. To facilitate theoverall loading process, a guide tube 64 with a length that is equal to,substantially equal to, or greater than an axial length of the main body30 of the loading apparatus 12 is considered particularly advantageous.

The guide tube 64 defines a guide passageway 63 through which thecannula 82, described below, can be inserted during a loading procedure.While the inclusion and use of the guide tube 64 is optional, it isconsidered advantageous at least because it provides a physical barrierbetween the expandable intraluminal medical device 20 and the cannula 82during a loading procedure. This barrier can protect the expandableintraluminal medical device 20 from potential damage-causing contactwith the cannula 82. This can be particularly advantageous forexpandable intraluminal medical devices that include a graft member,tissue section, or other component that might be susceptible to damageduring contact with components like the cannula 82. Following initialinsertion of the cannula 82, the guide tube 64 can be removed.

The guide tube 64 can be formed of any suitable material, includingmetal, glass, plastic, rubber, and other materials. The use of aflexible material is considered advantageous at least because itfacilitates removal of the guide tube 64 following insertion of theelongate cannula 82 during a loading procedure. The guide tube 64 hasproximal 65 and distal 67 ends. At least one of the ends 65, 67 is opento allow insertion of the cannula 82 during a loading procedure.Advantageously, one of the ends 65, 67 is closed, either by inclusion ofa plug, cap, or other closure member, or by the inclusion of a closedend on the tube 64. The end 65, 67 that is closed should be opposite theend 65, 67 into which the cannula 82 will be inserted during a loadingprocedure. This arrangement ensures that the guide tube 64 is forced outof the loading apparatus 12 by the cannula 82 by its passage into thetube 64. In the illustrated embodiment, the proximal end 65 is closedand the distal end 67 is open, providing access to the guide passageway63. Passage of the elongate cannula 82 through the distal end 67 andinto the guide passageway 63, as described below, will force the guidetube 64 out of the loading apparatus 12 as the elongate cannula 82contacts the closed proximal end 65 and is continually advanced in aproximal direction. This ensures that the guide tube 64 is removed fromthe loading apparatus 12 during the loading procedure.

A cap 66 is disposed on the main body 30 at the proximal opening 38. Thecap defines an opening 69 through which the guide tube 64, if present,can extend. The cannula 82 of the distal tip member 80 and an outertubular member 106 of the delivery catheter 14 can also be passedthrough the opening 69 during a loading procedure, as described below.Pull wires 68 a, 68 b are attached to cap 66 and to a structural featureof the expandable intraluminal medical device 20. As a result of theseattachments, the cap 66 can be used to pull the expandable intraluminalmedical device 20 through a portion of the passageway 36, such as fromthe distal chamber 44, through the transition chamber 46, and into theproximal chamber 42. A tether wire 70 is attached to the cap 66 and tothe main body 30. The tether wire 70 advantageously has a length thatprevents such axial movement of the expandable intraluminal medicaldevice 20 beyond a desired stopping point, such as a location within theproximal chamber 42. Thus, the tether wire advantageously has a lengththat is less than the axial length of the main body. Moreadvantageously, the tether wire has a length that is less than half theaxial length of the main body.

Any suitable material can be used for the cap 66, including plastic,metal, glass, and rubber materials. Furthermore, the cap 66 can definestructural features, such as a thread, shoulder, an included magnet orother structure that facilitates attachment to the proximal end 32 ofthe main body 30, which can define or otherwise provide suitablecomplimentary structure and/or features. Separate members can also beused to form a connection between the cap 66 and the main body 30, suchas clamps and the like. As best illustrated in FIG. 2, cap 66advantageously includes separable portions 66 a, 66 b. The separableportions 66 a, 66 b can be connected to each other by mating threads, asillustrated, or by any other suitable structure or components. Theinclusion of separable portions 66 a, 66 b is considered advantageous atleast because it allows the pull wires 68 a, 68 b, 68 c, 68 d to beclamped between the separable portions 66 a, 66 b during a loadingprocedure and removed from the expandable intraluminal medical device 20following the procedure without requiring cutting of the wires. Forexample, the separable portions 66 a, 66 b can simply be disconnectedfrom each other, or loosened relative to each other, allowing the pullwires 68 a, 68 b, 68 c, 68 d to simply be pulled through a loop or otherstructural feature on the expandable intraluminal medical device 20 andremoved.

Any suitable material can be used for the pull wires 68 a, 68 b, 68 c,68 d and the tether wire 70. As used herein, the term “wire” does notrequire any specific material or type of material and is used only tomean an elongate structure capable of being used as described herein.The term requires no specific degree of rigidity or stiffness. Examplesof suitable materials include metal, plastic, and fibrous materials.Wires, strings, and sutures can be used for both the pull wires 68 a, 68b, 68 c, 68 d and the tether wire 70. Furthermore, while four pull wires68 a, 68 b, 68 c, 68 d are illustrated and described, and a singletether wire 70 is illustrated and described, any suitable number,configuration and arrangement can be used for each of these elements.The tether wire 70 is advantageously shorter in length than all of thepull wires 68 a, 68 b, 68 c, 68 d, thereby providing the desiredmechanical stop.

As will be described more fully below, the pull wires 68 a, 68 b, 68 c,68 d are advantageously disconnected from at least the expandableintraluminal medical device 20 after the device 20 has been moved intothe proximal chamber 42. As such, a material that facilitates suchdisconnection is considered advantageous. A simple suture looped througha portion of a support frame of an expandable intraluminal medicaldevice is considered particularly advantageous for this reason—suturescan be readily cut and removed using scissors or another cuttinginstrument.

Alternatively, one or more stiff wire members that define appropriatestructure for releasably engaging the expandable intraluminal medicaldevice 20 can be used as the pull wires. For example, one or more wiremembers that define a helical structure at the distal end thereof can beused. The helical structure(s) can be releasably wound around a portionof the expandable intraluminal medical device, such as a strut orportion of a strut that is free of contact with an included graft orattached functional component of the device. In this embodiment, thepull wire(s) can be disconnected from the expandable intraluminalmedical device following pulling of the device into the compressedconfiguration by rotating the pull wire(s) about a longitudinal axiswhile gently pulling back on the wire(s), effectively unwinding thewire(s) from around the strut or portion of a strut around which thedistal end is wound. FIG. 8A illustrates a wire member 400 that definesa helical structure 402 at its distal end 404. FIG. 8B illustrates thehelical structure 402 wound around a strut 460 of a support frame 452,which is part of an expandable intraluminal medical device 450. FIG. 8Cillustrates the helical structure 402 would around a strut 480 of asupport frame 472, which is part of an expandable intraluminal medicaldevice 470. The expandable intraluminal medical device 470 includes agraft member 474, which can comprise a section of tissue attached to thesupport frame 472. In this embodiment, the helical structure 402 iswound around the strut 480 such that portions 490 of the helicalstructure 402 are disposed between the graft member 474 and the strut480. FIG. 8D illustrates first 510 and second 512 wire members. Thefirst wire member defines a first helical structure 520 and the secondwire member 512 defines a second helical structure 522. Each helicalstructure 520, 522 is would around a strut 530, 532 of a support frame540, which is part of an expandable intraluminal medical device 550.Similar to the embodiment illustrated in FIG. 8C, the expandableintraluminal medical device 550 includes a graft member 552 attached tothe support frame 540. In this embodiment, each helical structure 520,522 is wound around a strut 530, 532 such that portions 560 of thehelical structure 520, 522 are disposed between the graft member 552 andthe strut 530, 532. The expandable intraluminal medical device 550 inthis embodiment is similar to the implantable valve devices described inUnited States Patent Application Publication No. 2009/0105813 toChambers, et al., for an IMPLANTABLE VALVE DEVICE, the entire contentsof which are incorporated into this disclosure by reference for thepurpose of describing suitable expandable intraluminal medical devicesfor use with the loading apparatuses, systems and methods describedherein.

Also, as described above, the cap 66 can include separable portions 66a, 66 b. In these embodiments, each pull wire 68 a, 68 b, 68 c, 68 d cansimply be looped through a structural feature on the expandableintraluminal medical device 20, such as a loop, hook, eyelet, an othersuitable structure defining an opening in a support frame, or any othersuitable structure, and clamped between the separable portions 66 a, 66b of the cap 66. After the expandable intraluminal medical device 20 hasbeen moved into the proximal chamber 42, the pull wires 68 a, 68 b, 68c, 68 d can be removed simply by separating the separable portions 66 a,66 b of the cap 66 from each other, or by completely disconnecting theportions 66 a, 66 b from each other, effectively removing the clampingforce on the pull wires 68 a, 68 b, 68 c, 68 d, and pulling the pullwires 68 a, 68 b, 68 c, 68 d through their connection to the expandableintraluminal medical device 20. This structural arrangement isconsidered advantageous at least because it eliminates the need to cutthe pull wires 68 a, 68 b, 68 c, 68 d following the step of pulling theexpandable intraluminal medical device 20 into the proximal chamber 42of the loading apparatus 12 during a loading procedure. This structuralarrangement of the cap 66 is considered particularly advantageous foruse with pull wires that comprise threads or other members of relativelylow rigidity.

The tether wire 70 advantageously is formed of a relatively durablematerial that does not cut easily, such as metal, plastic, or othersuitable material. The tether wire 70 is advantageously more stiffand/or more rigid than the pull wires 68 a, 68 b, 68 c, 68 d.

The delivery catheter 14 includes a tip member 80 comprising an elongatecannula 82 with a distal tip body 84 disposed on a distal end thereof.The distal tip body 84 includes a tapered proximal surface 86 and atapered distal surface 88. The distal tip body 84 defines a distalopening 90 that provides access to a passageway 92 defined by theelongate cannula 82 and that extends between and through the proximal 83and distal 85 ends of the cannula 82.

The delivery catheter 14 also includes an elongate main body 94 having aproximal end (not shown in the Figures) and a distal end 98. A distalsurface 100 defines a distal opening 102 that provides access to apassageway 104 that extends between the proximal and distal 98 ends. Theelongate cannula 82 is adapted to be slideably disposed within thepassageway 104.

An outer elongate tubular member 106 provides a sheath that defines asheath lumen 108. The elongate main body 94 is slideably disposed withinthe sheath lumen 108. A handle 110 or other desirable apparatus isattached to the proximal end of the tubular member 106.

Stiffening mandrel 16 has an elongate body 112 adapted to be slideablydisposed through the passageway 104 defined by the main body 94 and thepassageway 92 defined by the distal tip member 80. A knob 114 isdisposed on a proximal end of the elongate body 112 and provides amechanical stop that prevents further distal advancement of the mandrel16 into the passageway 104. Inclusion of the mandrel 16 is consideredoptional. The inventors have determined that inclusion of the mandrel 16is advantageous when the cannula 82 is formed of a relatively softmaterial with insufficient column strength, such as plastic materials,for use in loading procedures that use the loading apparatus 12, such asthe methods described herein. In embodiments in which the cannula 82 isformed of a relatively rigid material that provides sufficient columnstrength, such as stainless steel, the inventors have determined thatinclusion of the mandrel 16 is not necessary.

The various components of the delivery catheter 14 can be formed of anysuitable materials, including conventional delivery system materialsknown in the art. For example, the distal tip member 80 is adapted to beinserted into and navigated through a body vessel into which thedelivery catheter 14 is intended to deliver the expandable intraluminalmedical device 20. As such, the distal tip body 84 advantageously isformed of a plastic material as is known in the art. Also, a relativelysoft and/or pliable material can be used. The elongate cannula 82 can beformed of metal, plastic or other suitable material. The elongate mainbody 94 and elongate tubular member 106 are advantageously formed ofplastic materials. The stiffening mandrel 16 advantageously comprises asolid metal member, although plastic and other materials can be used.

As best illustrated in FIG. 3, the inner sleeve 18 has a tubular body116 with proximal 118 and distal 120 ends. The proximal end 118 definesa proximal opening 122 and the distal end 120 defines a distal opening124. A passageway 126 extends between the proximal 122 and distal 124openings. The proximal end 118 defines a proximal detent 128 adapted toprevent distally-directed entry of the outer elongate tubular member 106of the delivery catheter 14 into the passageway 126 of the inner sleeve18. Advantageously, as best illustrated in FIG. 3, the proximal detent128 comprises an inwardly-directed circumferential taper, the outersurface of which provides the desired prevention of distally-directedentry of the outer elongate tubular member 106 into the passageway 126and the inner surface of which slightly compresses the expandableintraluminal medical device 20 as it transitions from the passageway 126and into the sheath lumen 108, as described below. This slightcompression of the expandable intraluminal medical device 20 provides amechanical lead-in for the device 20 so that it does not engage theleading distal edge of the outer elongate tubular member 106 of thedelivery catheter 14.

The distal end 120 of the inner sleeve 18 advantageously defines adistal flange 130. Advantageously, the distal flange 130 comprises anoutwardly-directed circumferential taper. As best illustrated in FIG. 1,the distal flange 130 is disposed between the proximal surface 131 ofthe distal portion 62 of the loading apparatus 12 and the mating distalsurface 133 of the proximal portion 60 of the loading apparatus 12. Thisstructural arrangement holds the inner sleeve 18 captive between theproximal 60 and distal 62 portions of the loading apparatus 12,preventing proximal and distal movement of the inner sleeve 18 when theproximal 60 and distal 62 portions are connected to each other viaseparable connection 58. This captive arrangement ensures that the innersleeve 18 will provide the desired lead-in functionality during aloading procedure, and facilitates removal of the sleeve 18 followingmovement of the expandable intraluminal medical device 20 into thedelivery catheter 14 (see below).

Inclusion of the inner sleeve 18 provides a separate component that hasan inner diameter that is smaller than the inner diameter of the outerelongate tubular member 106 of the delivery catheter 14.

The inner sleeve 18 can be formed of any suitable material, and askilled artisan can select an appropriate material for a systemaccording to a particular embodiment based on various considerations,including the structure of the expandable intraluminal medical device 20and the nature of the materials used in the device 20. Examples ofsuitable materials for the sleeve 18 include metal, glass, plastic andother polymeric materials. Considering the sliding movement of theexpandable intraluminal medical device 20 through the inner sleeve 18during a loading procedure, it is considered advantageous to form theinner sleeve 18 of a material that provides a relatively low coefficientof friction with regard to the expandable intraluminal medical device20. In this regard, a stiff, relatively thin-walled tubular memberformed of a polymeric material, such as polypropylene, is consideredadvantageous. A material that provides a relatively low coefficient offriction in relation to the material of the loading apparatus 12 isconsidered advantageous. Fluoropolymers are considered particularlyadvantageous at least because of the degree of stiffness and desirablefrictional properties they provide. Fluorinatedethylenepropylene (FEP)(available from Zeus, Inc., Orangeburg, S.C.) is considered aparticularly advantageous material for the inner sleeve 18. Furthermore,portions of the inner sleeve 18, or the entire sleeve 18, can be coatedwith a suitable lubricious coating, such as parylene-C or any othersuitable coating, to facilitate movement of the expandable intraluminalmedical device 20 through the sleeve 18. For example, the entire innersurface of the inner sleeve 18 can be coated, if desired.

The inner sleeve 18 can have any suitable size and configuration, and askilled artisan will be able to select suitable parameters based onvarious considerations, including the size and configuration of theloading apparatus 12 of the loading apparatus, the size andconfiguration of the expandable intraluminal medical device 20, and thesize and configuration of the delivery catheter 14. The inventors havedetermined that an inner sleeve 18 that has an inner diameter that isone French size (about 0.013″) smaller than the inner diameter of theouter elongate tubular member 106 is suitable. This relativedimensioning provides sufficient tolerance difference to account fordimensional stack up and is readily manufacturable. Thus, the size andconfiguration of the loading apparatus 12 and inner sleeve 18 can bedetermined based on the inner and outer diameters of a delivery catheterwith which the loading apparatus 12 and inner sleeve 18 are intended towork. The inventors have determined that an inner sleeve comprising FEPwith a wall thickness of about 0.0125″ is suitable for use with avariety of loading apparatuses and expandable intraluminal medicaldevices.

FIG. 4 illustrates a loading apparatus 12′ according to an alternateembodiment in which the main body 30′ defines a circumferential edge 31′that leads into an outer elongate tubular member 106′ of a deliverycatheter 14′ that has been disposed in the proximal chamber 42′. Thecircumferential edge 31′ defines an inner diameter that is less than aninner diameter of the outer elongate tubular member 106′ and, as such,protects the distal end of the outer elongate tubular member 106′ fromengagement with an expandable intraluminal medical device (notillustrated in FIG. 4) during a loading procedure. Accordingly, when anexpandable intraluminal medical device is pushed through the main body30′, the circumferential edge 31′ provides a mechanical lead-in to theouter elongate tubular member 106′ that eliminates the need for theinner sleeve used in the first embodiment described above andillustrated in FIGS. 1, 1A, 2 and 3. The structure of this alternateembodiment is considered advantageous at least because it eliminates theneed for the inner sleeve, as described below. The structure of thisembodiment also eliminates the need for inclusion of the separableconnection used in the first embodiment because it eliminates the needfor the inner sleeve and, consequently, the need to remove the sleevefrom the loading apparatus following a loading procedure. The main body30′ of this embodiment, however, has a minimum inner diameter thatprevents its passage over a distal tip body, such as distal tip body 84of distal tip member 80 illustrated in FIG. 1. Thus, use of a distal tipmember that includes a removable portion of the distal tip body, such asthat illustrated in FIG. 6, is considered advantageous when using aloading apparatus 12′ according to this embodiment.

The expandable intraluminal medical device 20 has radially-expanded andradially-compressed configurations. That is, the expandable intraluminalmedical device 20 has an expanded configuration in which the device hasa first, relatively large diameter and a compressed configuration inwhich the device has a second, relatively small diameter. A variety ofexpandable intraluminal medical devices are known in the art, and theexpandable intraluminal medical device 20 can comprise any suitableexpandable intraluminal medical device, such as a stent, a stent-graft,a prosthetic valve, an occluder, a filter, and any other type ofexpandable intraluminal medical device now known or later developed.Furthermore, the expandable intraluminal medical device 20 can be aself-expandable medical device or a device that requires an applicationof an expansion force to achieve radial expansion and the expandedconfiguration, such as a balloon-expandable medical device. Thedisclosed apparatuses, systems, kits and methods are particularlywell-suited, however, for use with self-expandable intraluminal medicaldevices, such as expandable intraluminal medical devices that include aself-expandable support frame.

The system 10 and various components are particularly well-suited foruse with expandable intraluminal medical devices for which loading thedevice into a selected delivery device immediately prior to a treatmentprocedure is recommended or otherwise considered desirable. Examples ofsuch expandable intraluminal medical devices include stents withbiologically-active coatings, stents with attached grafts, includinggrafts of biological origin, and tissue-based prosthetic valve devices,such as prosthetic heart valve and prosthetic venous valves that includeone or more section of tissue, tissue-derived material, or otherflexible material.

The inventors have determined that the system 10 and various componentsare particularly well-suited for use with expandable intraluminalmedical devices that include a support frame 132 and an attached sectionof material 134, such as a section of tissue. As best illustrated inFIG. 1A, the support frame 132 advantageously defines a suitable numberof connectors 136, such as loops, openings, hooks, posts, eyelets,fillets or other suitable structural features that are adapted to engagepull wires 68 a, 68 b as described above.

Examples of suitable expandable intraluminal medical devices for use inthe systems according to this disclosure are described in United StatesPatent Application Publication No. 2009/0105813 for IMPLANTABLE VALVEDEVICE, the entire contents of which are hereby incorporated byreference into this disclosure.

Pusher 22 includes first 140 a and second 140 b pushing arms. Each arm140 a, 140 b terminates in a pushing surface 142 a, 142 b at theproximal end 144 a, 144 b and is attached to a base 146 at its distalend 148 a, 148 b. Each of the pushing arms 140 a, 140 b is an elongatemember having an outward bias and a semi-circular cross-sectional shape,which facilitates the advancing and loading of intraluminal medicaldevice 20. While two pushing arms 140 a, 140 b are illustrated in theFigures, it is expressly understood that any suitable number of pushingarms can be used, and the exact number included in a loading systemaccording to a particular embodiment will depend on severalconsiderations, including the nature of the intraluminal medical devicebeing used with the system and the size of the loading apparatus.Embodiments having between two and five pushing arms are consideredadvantageous at least because the inclusion of multiple arms candistribute a pushing force applied by the arms across multiple points onthe intraluminal medical device 20. Nevertheless, an embodiment with asingle pushing arm is considered acceptable at least because the columnstrength achieved in the intraluminal medical device 20 once it isplaced in the radially-compressed configuration in the loading apparatus12 is expected to be sufficient to avoid any uneven pushing placed onthe device as a result of the use of only a single pushing arm. It isalso noted that while the pushing arms 140 a, 140 b are shown in asubstantially opposing arrangement, any suitable arrangement can beused. Pushing arms arranged equidistant from each other relative to acentral axis of the pusher 22 are considered advantageous at leastbecause such an arrangement results in an even application of a pushingforce onto the expandable intraluminal medical device 20 duringadvancement through the passageway 36 of the loading apparatus 12.

The pushing arms 140 a, 140 b can contact and/or interact with theintraluminal medical device 20 in any suitable manner. The proximal ends144 a, 144 b of the pushing arms 140 a, 140 b advantageously includestructure that facilitates a desired contact and/or interaction for aloading system according to a particular embodiment of the invention.The illustrated pushing arms 140 a, 140 b include blunt proximal ends144 a, 144 b that interact with a distal end of the expandableintraluminal medical device 20. Alternative structures include achannel, notch, loop, hook, or other suitable structure that accepts abarb or other portion of a support frame of the intraluminal medicaldevice 20. The inclusion of structure that allows for a mechanicalengagement between the pushing arms 140 a, 140 b and the expandableintraluminal medical device 20 is considered optional because therelatively high column strength achieved in the expandable intraluminalmedical device 20 once it is placed in the radially-compressedconfiguration inside the loading apparatus 12 is expected to be greatenough that the inclusion of blunt proximal ends 144 a, 144 b issufficient to achieve the desired movement of the expandableintraluminal medical device 20 along the lengthwise axis of the loadingapparatus 12 and into the delivery catheter 14.

While not currently preferred, it is noted that the pushing arms 140 a,140 b can be configured and used to contact another portion of theexpandable intraluminal medical device 20, such as a proximal end of thedevice 20 or even an intermediate portion of the device 20. Furthermore,the pushing arms 140 a, 140 b can be configured and/or arranged toachieve the desired advancement of the expandable intraluminal medicaldevice 20 by application of a compressive force onto the intraluminalmedical device 20 or by an application of tension to a portion of thedevice 20.

Examples of suitable pushers for use in the systems according to thisdisclosure are described in United States Patent Application PublicationNo. 2009/0143857 to Melsheimer, et al., for TAPERED LOADING SYSTEM FORIMPLANTABLE MEDICAL DEVICES, the entire contents of which are herebyincorporated by reference into this disclosure.

FIGS. 5A through 5F illustrate use of a loading apparatus according tothe first embodiment.

In an initial step of a loading method, illustrated in FIG. 5A, theproximal 60 and distal 62 portions of the main body 30 of the loadingapparatus 12 are connected at separable connection 58. The guide tube 64is positioned in the passageway 36. The proximal end 83 of elongatecannula 82 has been inserted into the distal opening 40 of the loadingapparatus 12 and into the guide passageway 63 of the guide tube 64.distal flange 130 of inner sleeve 18 is held captive between theproximal 60 and distal 62 portions of the main body 30, which areconnected to each other via separable connection 58. The tubular body116 of the inner sleeve 18 is disposed within the portion of thepassageway 36 within the proximal portion 60 of the main body 30.

During this stage of loading, the expandable intraluminal medical device20 is disposed in the distal chamber 44 of the loading apparatus 12 andis in a radially-expanded configuration.

In another step of a loading method, illustrated in FIG. 5B, theproximal end 83 of the elongate cannula 82 has been advanced proximallythrough the loading apparatus 12 and guide tube 64. Contact between theproximal end 83 of the elongate cannula 82 and the proximal end 65 ofthe guide tube 64, which is a closed end, has forced the guide tube 64partially out of the loading apparatus 12. Once the guide tube 64 hascompletely exited the loading apparatus 12, the user can remove it fromthe loading apparatus 12 and discard it.

In another step of a loading method, illustrated in FIG. 5C, the cap 66has been pulled in the direction represented by arrow 150. As a result,pull wires 68 a, 68 b, 68 c, 68 d have pulled the expandableintraluminal medical device 20 through the transition chamber 46 andinto the inner sleeve 18 and the proximal chamber 42. The expandableintraluminal medical device 20 is in a radially-compressed configurationin this stage of loading. Tether 70 is taught, preventing furtherproximally-directed axial movement of the cap 66, pull wires 68 a, 68 b,68 c, 68 d, and, as a result, the expandable intraluminal medical device20.

In another step of a loading method, illustrated in FIG. 5D, theseparable portions 66 a, 66 b of the cap 66 have been separated fromeach other and the pull wires have been removed from the loadingapparatus 12 and their engagement with the expandable intraluminalmedical device 20. The proximal end (not illustrated in FIG. 5D) of thecannula 82, which extends through the proximal opening 38 of the loadingapparatus 12, has been passed into the distal opening 102 of the mainbody 94 of the delivery catheter 14. Also, following removal of the pullwires from the loading apparatus 12 and their engagement with theexpandable intraluminal medical device 20, the distal end of thedelivery catheter 14 has been inserted into and through the proximalopening 38 of the main body 30 and into the portion of the passageway 36defined by the proximal portion 60 of the main body 30 of the loadingapparatus 12. The elongate cannula 82 has been extended through thepassageway 104 of the elongate main body 94 of the delivery catheter 14so that the distal tip body 84 is positioned within the portion of thepassageway 36 defined by the distal portion 62 of the loading apparatus12.

Pushing arms 140 a, 140 b of pusher 22 have been inserted into thedistal opening 40 of the loading apparatus 12 to engage the expandableintraluminal medical device 20. The outer elongate tubular member 106 ofthe delivery catheter 14 has been advanced distally to engage theproximal detent 128 of the inner sleeve 18. Main body 94 of deliverycatheter 14 has been retracted from the distal end of the outer elongatetubular member 106, creating a device chamber 160 between the distalsurface 100 of the main body 94 and the distal end of the outer elongatetubular member 106. An inner surface of the outer elongate tubularmember 106 defines the outer surface of the device chamber 160. Theelongate cannula 82 passes through the device chamber 160 and into thedistal opening 102 of the main body 94.

To load the expandable intraluminal medical device 20 into the devicechamber 160, a user can apply proximally-directed force to pushing arms140 a, 140 b, in the direction represented by arrow 170 while holdingthe delivery catheter 14 and loading apparatus 12 stationary. Adistally-directed force can be applied to the delivery catheter 14 inthe direction represented by arrow 172 to resist movement of componentsof delivery catheter 14 as a result of the proximally-directed force170.

Following the application of the proximally-directed force 170, theexpandable intraluminal medical device 20 is disposed within the devicechamber 160, as represented in FIG. 5E. At this time, the inner sleeve18 remains surrounding the elongate cannula 82 and captive in theloading apparatus 12 between the proximal 60 and distal 62 portions ofthe main body 30.

To complete the loading process, the separable connection 58 isdisrupted by applying opposing rotational forces, represented by arrows174, 176 in FIG. 4F (or by other appropriate disruption based on thestructure and/or properties of separable connection 58). The distalportion 62 of the loading apparatus 12 is then moved distally,represented by arrow 178, until it passes over the distal tip body 84.The distal portion 62 is then free of the delivery catheter. The innersleeve 18, the inner diameter of which is smaller than the outerdiameter of the distal tip body 84, is then cut lengthwise, or otherwisedisrupted structurally along its length, to allow it to be removed fromits position surrounding the elongate cannula 82. The proximal portion60 of the loading apparatus 12, which is prevented from being passedover the distal tip body 84 before the inner sleeve 18 is removed, isthen moved distally, represented by arrow 178, until it passes over thedistal tip body 84 and is then free of the delivery catheter. At thispoint, the entire loading apparatus 12 is free of the delivery catheter14. The cap 66, which was previously captive and surrounding outerelongate tubular member 106 of the delivery catheter 14, can also beremoved at this point.

To complete the loading process, the distal tip body 84 is positionedsuch that the tapered proximal surface 86 or other portion of the distaltip body 84 engages the distal end of the outer elongate tubular member106 of the delivery catheter 14. This can be accomplished either bymoving the elongate cannula 82 in a proximal direction while holding thedelivery catheter 14 steady, or by moving the outer elongate tubularmember 106 and main body 94, and the expandable intraluminal medicaldevice, in a distal direction while holding the elongate cannula 82steady. When accomplishing this positioning using the later approach,care should be exercised to ensure that that loaded expandableintraluminal medical device 20 is not moved out of its position in thedevice chamber 160.

FIG. 6 is an exploded view of a system 210 for loading an expandableintraluminal medical device into a delivery catheter according to ananother embodiment. The system 210 is similar to the system 10illustrated in other figures and described above, except as detailedbelow. Thus, the system 210 includes loading apparatus 212, deliverycatheter 214, expandable intraluminal medical device 220, guide tube264, and distal tip member 280. As with the first embodiment describedabove, a user can load the expandable intraluminal medical device 220into the delivery catheter 214 by advancing a distal portion of thedelivery catheter 214 into a proximal portion of the loading apparatus212; pulling the radially-expanded expandable intraluminal medicaldevice 220 proximally along a lengthwise axis of the loading apparatus212 to position it within the proximal, or narrow, chamber of theloading apparatus 212, effectively transitioning the expandableintraluminal medical device 220 from a radially-expanded configurationto a radially-compressed configuration; pushing the radially-compressedexpandable intraluminal medical device 220 proximally along thelengthwise axis of the loading apparatus 212 to move the expandableintraluminal medical device 220 from the proximal chamber of the loadingapparatus 212 into the distal portion of the delivery catheter 214; andremoving the delivery catheter 214 from the loading apparatus 212.During the loading process, the expandable intraluminal medical device220 transitions from a radially-expanded configuration to aradially-compressed configuration.

In this embodiment, the distal tip member 280 includes a separableconnection 283 that, when disrupted, separates the distal tip member 280into proximal 285 and distal 287 portions. The proximal portion 285includes the elongate cannula 282 and a portion of the distal tip body284. The distal portion 287 includes the remaining portion of the distaltip body 284. The separable connection 283 is located on a lengthwiseaxis of the distal tip body 284 to place the separating line 289 formedby the separable connection 283 on the tapered proximal surface 286, orotherwise proximal to the maximum outer diameter of the distal tip body284. Positioning the separable connection 283 in this manner eliminatesthe need for the separable connection in the main body 230 of theloading apparatus 212 (as included in the embodiment illustrated in FIG.1). When the separable connection 283 is disrupted, the distal tip body284 can be removed temporarily. The outer diameter of the remainingportion of the elongate cannula 282, and any remaining portion of thedistal tip body 284, is small enough to allow the entire loadingapparatus 212 to be passed over it with distal movement following aloading procedure. Furthermore, as illustrated in FIG. 6, positioningthe separable connection 283 such that the separating line is within theaxial length of the tapered proximal surface provides anoutwardly-directed flare that can be used to pull the expandableintraluminal medical device 220 into the transition chamber 246 during aloading procedure. As such, the inclusion of a pusher, such as thepusher 22 of the first embodiment, is considered optional in thisembodiment.

The inclusion of the separable connection 283 in the distal tip body 284is also considered advantageous because it eliminates the need forinclusion of a separate inner sleeve that guides the expandableintraluminal medical device 220 into the delivery catheter 214. In thisembodiment, because a portion of the distal tip body 284 can be removed,the inner diameter of the loading apparatus 212 can be made smaller thanthe inner diameter of the outer elongate tubular member 215 of thedelivery catheter 214 because there is no need to accommodate the largerouter diameter of the portion of the distal tip body 284 that can beremoved from the distal tip member 280 (i.e., there is no need to passthe distal tip body 284 through the entire loading apparatus 212; thus,an inner diameter of a portion of the loading apparatus 212 can be madesmaller than the inner diameter of the outer elongate tubular member215).

It is noted that an inner sleeve, such as inner sleeve 18 illustrated inFIG. 3, can be used, though, with this embodiment if desired. If asleeve is included, the main body 230 still need not include a separableconnection because the remaining portion of the distal tip member 280,following disconnection of the portion of the distal tip body 284 viaseparable connection 283, can be passed through the sleeve to complete aloading procedure. If a sleeve is included, though, it is consideredadvantageous to use a main body that maintains the sleeve captivebetween proximal and distal portions thereof, as illustrated in FIG. 1.This arrangement ensures that the sleeve remains captive during use ofthe loading apparatus and eliminates the possibility that it would bemishandled or misplaced. In one such embodiment, the main body includesa separable connection, such as illustrated in FIG. 1. The proximal anddistal portions of the main body are, however, permanently affixed toeach other, such as by adhesive or other means for fixedly attaching twoportions of a component to each other, following placement of the sleevebetween these portions.

While a threaded connection is illustrated for the separable connection283, it is expressly understood that any suitable separable connectioncan be used for joining the proximal 285 and distal 287 portions of thedistal tip member 280. A skilled artisan will be able to select anappropriate separable connection based on various considerations,including the material(s) used for the distal tip member 280 and thedesired ease with which the separable connection 283 should be able tobe operated to achieve separation of the proximal 285 and distal 287portions. Other examples of suitable separable connections includemagnetic connections, mechanical connections, such as twist andlock-type connections, clamp connections, and the like.

As an alternative to separable connection 283, a distal tip memberhaving a collapsible distal tip body, such as a fluid-filled andevacuable distal tip body, can be used to achieve a reduction in outerdiameter of the distal tip body during a loading procedure, which wouldallow the distal tip body to pass through the entire loading apparatus212 and into the delivery catheter 214 to complete the procedure.

FIG. 7 illustrates a kit 300 useful in the preparation of an expandableintraluminal medical device for implantation in a patient. The kit 300includes a loading apparatus 302 according to an embodiment of theinvention, an expandable intraluminal medical device 304, and a deliverycatheter 306. Optional components to the kit include an inner sleeve308, a pusher 310, instructions 312 for practicing a method according toan embodiment of the invention, and a container 314 for holding thevarious components of the kit 300.

While the embodiments described herein relate to a loading system, theinventors expressly contemplate the use of the various components hereinas a storage system as well. For example, an expandable intraluminalmedical device can be placed within a loading apparatus and storedtherein, such as in a distal chamber in an expanded configuration, for aperiod of time. In these embodiments, the loading apparatus can includecaps that seal the openings at the proximal and distal ends of theloading apparatus. A storage fluid can be contained within the apparatusin these embodiments, if desired. Indeed, appropriate caps can beprovided such that the loading apparatus can be placed on the deliverycatheter during storage, allowing an end-user to proceed directly toloading once the delivery catheter is selected for use. Also, a loadingapparatus can be stored in a storage container that includes a storagefluid and/or sealing member, such as a cap. For example, in oneembodiment, an expandable intraluminal medical device can be placedwithin a loading apparatus and stored therein, such as in a distalchamber in an expanded configuration, for a period of time. This loadingapparatus can then be placed within a storage chamber, such as a glassor plastic tube with one or more closures. Saline or another appropriatestorage fluid can be placed within the storage container such that theexpandable intraluminal medical device is in contact with the storagefluid, and the closure can be sealed, such as with a cap or othersuitable means for closing the storage container. In this arrangement,the expandable intraluminal medical device can be stored in the loadingapparatus, ready for a loading procedure, for an extended period oftime.

The inventors consider it advantageous to supply the expandableintraluminal medical device to end users of the loading apparatus and/orsystem as disposed within the loading apparatus and ready for use in aloading procedure, such as disposed in the distal chamber of a loadingapparatus in a radially-expanded configuration. Furthermore, ifincluded, an inner sleeve is advantageously supplied to the end user inplace within the loading apparatus and ready for use, such as captivebetween proximal and distal portions of a loading apparatus thatincludes a separable connection. These placements of these componentsensure that the user can quickly initiate a loading procedure withoutconcern for any pre-positioning and/or assembly steps, which mightotherwise introduce variability into performance of the loadingprocedure. Kits according to the invention advantageously include thecomponents arranged in this manner.

Methods of loading an expandable intraluminal medical devices into adelivery catheter are also provided. Exemplary methods include one stepof pulling an expandable intraluminal medical device along an axial pathand through an apparatus such that the expandable intraluminal medicaldevice transitions from a radially-expanded configuration to aradially-compressed configuration, and another step of pushing theradially-compressed expandable intraluminal medical device along anaxial path and into the distal end of the delivery catheter. The pullingand pushing steps advantageously produce movement of the expandableintraluminal medical device along a singular axial path, althoughmovement along different and/or distinct paths can also be utilized.Furthermore, both of the pulling and pushing steps advantageouslycomprise translational movement (i.e., movement without rotation of theexpandable intraluminal medical device). Substantially translationalmovement during one or both of the pulling and pushing steps is alsoconsidered suitable. Furthermore, axial movement accompanied byrotational movement of the expandable intraluminal medical device isalso considered suitable for one or both of the pulling and pushingsteps.

The inclusion of a pulling step is advantageous because expandableintraluminal medical devices, when in a radially-expanded configuration,are difficult to push into a delivery system. Application of a pushingforce on an expandable intraluminal medical device, when in theradially-expanded configuration, is an ineffective way to move suchdevices along a path because the expanded device typically lackssufficient column strength that would allow the pushing force to achievesuch movement. This is particularly true for self-expandableintraluminal medical devices, such as those made of Nitinol and otherflexible materials. Furthermore, the application of greater pushingforce in an attempt to overcome this ineffectiveness may lead to damageto the device or an attached component, such as a graft, leaflet, orother component.

The inclusion of a pushing step, following the step of pulling theexpandable intraluminal medical device into a radially-compressedconfiguration, is advantageous at least because there is ofteninsufficient space in the loading apparatus, after the initial pullingstep, available for components necessary to achieve the additionalpulling that would be needed to accomplish the loading of the expandableintraluminal medical device into the delivery catheter. This isespecially true with loading apparatuses that receive a portion of thedelivery catheter, such as the outer elongate tubular member, or sheath,during the loading process, such as those described herein. For thesestructures, use of additional pulling force on the compressed devicewould require modification of the delivery catheter itself, such asinclusion of pull wires that run through at least a portion of thelength of the sheath.

In contrast, by including a pushing step, the pushing force can beapplied from the opposite end of the loading apparatus, i.e., the endthat does not receive the delivery catheter. This enables the loadingapparatuses to be used with delivery systems that do not include anyspecial structure for pulling the radially-compressed expandableintraluminal medical device into the delivery catheter.

An exemplary method of loading an expandable intraluminal medical deviceinto a delivery catheter includes the step of placing An expandableintraluminal medical device in a loading apparatus as described and/orclaimed herein such that the device is in a radially-expandedconfiguration within the loading apparatus. In another step, a distaltip member or other suitable inner member is passed through the loadingapparatus such that a distal tip of the distal tip member is disposeddistal to the expandable intraluminal medical device. In another step,the expandable intraluminal medical device is pulled through a portionof the loading apparatus such the device is compressed and placed in aradially-compressed configuration. This pulling step can be accomplishedusing appropriate structure, such as the pull wires described herein. Inanother step, the outer elongate tubular member, or sheath, of thedelivery catheter is placed into a proximal end of the loadingapparatus, proximal to the compressed expandable intraluminal medicaldevice. In another step, a pushing structure, such as those describedherein, is inserted into the distal end of the loading apparatus. Inanother step, the pushing structure is contacted with the distal end ofthe expandable intraluminal medical device. In another step, a pushingforce is applied to the pushing structure and, consequently, transferredonto the expandable intraluminal medical device. The pushing force isapplied until the expandable intraluminal medical device is disposedwithin the sheath of the delivery system. Advantageously, the pushingforce is applied until the expandable intraluminal medical device isdisposed entirely within the distal end of the sheath of the deliverycatheter, such as in a device chamber formed by the inner surface of theouter sheath and a distal end of an inner member of the catheter. Inanother step, the loading apparatus is removed from its positionsurrounding the distal tip member or other inner member. This step mayinclude disruption of a separable connection in the loading apparatus,such as that described above, and may also include disruption and/orremoval of an inner sleeve component, if used. Finally, the distal tipmember is moved proximally toward and/or into the outer elongate tubularmember, or sheath, of the delivery catheter until a desirable structuralarrangement between these elements is achieved, such as a structure thatprovides a smooth transition between a distal tip body of the distal tipmember and the outer surface of the outer elongate tubular member of thedelivery catheter. At this point, the expandable intraluminal medicaldevice is disposed within the delivery catheter and is ready fordeployment.

While exemplary methods include one step of pulling an expandableintraluminal medical device into a radially-compressed configuration andanother step of pushing the radially-compressed expandable intraluminalmedical device into a medical device delivery catheter, it is noted thatexclusive use of either a pushing force or a pulling force can be usedto fully translate the expandable intraluminal medical device throughthe loading apparatus and into a delivery catheter. Exclusive use of apushing force can be completed by simply pushing the radially-expandedmedical device through the loading apparatus and into the deliverycatheter. Use of the described and illustrated pusher, or anothersuitable structure, can be used in such methods. For exclusive use of apulling force, the delivery catheter would need to accommodate suitablestructure to achieve the desired movement. For example, pull wires,similar to those attached to the cap 66 in the embodiment illustrated inFIG. 1, could be attached to the expandable intraluminal medical deviceand passed through a portion or the entire length of the sheath lumen ofthe delivery catheter. A user could then pull the wires proximally toachieve axial movement of the expandable intraluminal medical devicethrough the loading apparatus and placement within the device chamber ofthe delivery catheter. During such axial movement, the expandableintraluminal medical device would transition from a radially-expandedconfiguration to a radially-compressed configuration.

Example Loading an Expandable Valve Device into a Delivery Catheter

The following example describes a method of loading an expandable valvedevice, which includes a self-expandable support frame and an attachedbioprosthetic valve, into a suitable medical device delivery catheter.The method uses a loading apparatus as described herein, including aninner sleeve. The expandable valve device is provided in the distalchamber of the loading apparatus, in a radially-expanded configuration,prior to initiation of the loading procedure. The valve device issimilar to the valve devices described in United States PatentApplication Publication No. 2009/0105813 (incorporated herein, seeabove). The loading apparatus is provided in an outer storage containerthat includes a storage fluid.

1. Using a hemostat/forceps, grab the loading apparatus, such as by theguide tube if included, and remove the loading apparatus from the outerstorage container, making sure that all of the storage fluid has drainedout of the bottom before removing completely.

2. Insert the proximal end of the elongate cannula of the distal tipmember into the distal end of the guide tube that is extended out of theloading apparatus and push until the elongate cannula is extends axiallybeyond both lengthwise ends of the loading apparatus. This will forcethe guide tube out of the proximal end of the loading apparatus. Discardthe guide tube.

3. Insert the proximal end of the elongate cannula into the distal endof the main body or pusher of the delivery catheter until the proximalend of the elongate cannula exits the proximal end of the deliverycatheter. At this time, the elongate cannula of the distal tip membercan optionally be immobilized temporarily with respect to the main bodyor pusher of the delivery catheter, i.e., temporarily fix thesecomponents in position relative to each other such that relativemovement between the components is not possible.

4. Pull back steadily on the cap such that the pull wires pull the valvedevice along the lengthwise axis of the loading apparatus, moving thevalve device from the distal chamber of the loading apparatus to theproximal chamber, and transitioning the valve device from aradially-expanded configuration to a radially-compressed configuration.Stop pulling once the tether wire is taught and/or the entire valvedevice is inside the proximal chamber (narrow chamber) of the loadingapparatus.

5. Separate the separable portions of the cap and pull the pull wiresthrough their engagement with the valve device. Discard the pull wires.The cap is captive between the delivery catheter and the loadingapparatus at this point.

6. Pull the proximal end of the main body or pusher of the deliverycatheter so that the distal end of the pusher is pulled into the sheathof the delivery catheter. The distal end should be retracted into thesheath by a length that provides a device chamber of suitable axiallength for receiving the valve device. Markings on the proximal end ofthe main body or pusher can be used to indicate a suitable positioningof the main body or pusher relative to the sheath.

7. Place the outer elongate tubular member, or sheath, of the deliverycatheter into the opening defined by the proximal (narrow) end of theloading apparatus. Advance the sheath distally into the apparatus as faras the apparatus will allow such that it engages the proximal end of theinner sleeve within the loading apparatus.

8. Insert the pusher into the distal end of the loading apparatus untilthe pushing surface contacts the distal end of the radially-compressedvalve device. Then, steadily and gently push the valve device into thedelivery catheter until the valve is completely inside the devicechamber defined by the sheath.

9. Disrupt the separable connection of the loading apparatus, such as byunscrewing the proximal and distal portions from each other, and removethe inner sleeve from around the cannula, such as by cutting the sleevealong its length.

10. Remove the loading apparatus components from around the elongatecannula by moving both components distally, passing over the distal tipbody of the distal tip member.

11. Remove the loading apparatus cap from its position around thedelivery catheter, such as by passing it completely over the distal endof the catheter and the distal tip body.

12. Advance the elongate cannula of the distal tip member proximallyinto the sheath until there is a smooth transition between the distaltip body and the sheath. If the distal tip member was temporarilyimmobilized with respect to the main body or pusher of the deliverycatheter, the immobilization should be removed prior to this step,allowing relative movement between the components.

At this point, the expandable valve device is loaded in the deliverycatheter and is ready for use. To prevent premature movement of theexpandable valve device from the device chamber, the elongate cannula ofthe distal tip member can again be immobilized temporarily with respectto the main body or pusher of the delivery catheter, i.e., temporarilyfix these components in position relative to each other such thatrelative movement between the components is not possible. If one or bothof the optional immobilization steps are desired, a pin vise or othersuitable apparatus can be used to temporarily lock the elongate cannulaof the distal tip member to the main body or pusher of the deliverycatheter.

The foregoing detailed description provides exemplary embodiments of theinvention and includes the best mode for practicing the invention. Thedescription and illustration of embodiments is intended only to provideexamples of the invention and not to limit the scope of the invention,or its protection, in any manner.

What is claimed is:
 1. A medical device loading system, comprising: aloading apparatus comprising a main body having a proximal end defininga proximal opening, a distal end defining a distal opening, and apassageway extending between the proximal and distal openings, thepassageway defining a proximal chamber having a first inner diameter, adistal chamber having a second inner diameter, and a transition chamberdisposed between the proximal and distal chambers, the second innerdiameter being greater than the first inner diameter and the transitionchamber having an inner diameter that transitions along an axial lengthof the transition chamber from the second inner diameter to the firstinner diameter; a delivery catheter comprising an outer tubular memberdefining a sheath lumen, a dilator body disposed within the sheath lumenand defining a dilator lumen, and a distal tip member comprising anelongate cannula and a distal tip body, the elongate cannula adapted tobe slideably disposed within the dilator lumen and the distal tip bodydefining an outer diameter that is smaller than the second innerdiameter and larger than the first inner diameter; and an expandableintraluminal medical device; wherein the distal tip member has aseparable connection that divides the distal tip member into a proximaldistal tip member portion and a distal distal tip member portion whendisrupted.
 2. The medical device loading system of claim 1, wherein theseparable connection is located on the distal tip body such that theproximal distal tip member portion includes a portion of the distal tipbody and the distal distal tip member portion includes a portion of thedistal tip body.
 3. The medical device loading system of claim 1,wherein the distal tip body has a tapered proximal surface.
 4. Themedical device loading system of claim 3, wherein the separableconnection is located proximal to a portion of the distal tip bodydefining the maximum outer diameter of the distal tip body.
 5. Themedical device loading system of claim 4, wherein the separableconnection is located on the tapered proximal surface of the distal tipbody.
 6. The medical device loading system of claim 4, wherein theseparable connection is located on the tapered proximal surface of thedistal tip body such that entire proximal distal tip member portion canbe passed through the passageway of the loading apparatus.
 7. Themedical device loading system of claim 1, wherein the separableconnection comprises a connection formed between mating threads.
 8. Themedical device loading system of claim 1, wherein the main body of theloading apparatus defines a continuous outer surface.
 9. The medicaldevice loading system of claim 1, further comprising a proximal capdisposed on the proximal end of the main body, the proximal cap defininga cap passageway in communication with the passageway of the main body;and at least one pull wire attached to the proximal cap and extendinginto the passageway of the main body.
 10. The medical device loadingsystem of claim 9, wherein the at least one pull wire comprises a memberselected from the group consisting of a thread, a string, and a suture.11. The medical device loading system of claim 10, wherein the at leastone pull wire comprises two or more pull wires.
 12. The medical deviceloading system of claim 9, further comprising a distal cap disposed onthe distal end of the main body.
 13. The medical device loading systemof claim 12, wherein the distal cap seals the distal opening of the mainbody.
 14. The medical device loading system of claim 13, wherein theproximal cap seals the proximal opening of the main body.
 15. Themedical device loading system of claim 14, further comprising a storagefluid disposed within the passageway of the main body.
 16. The medicaldevice loading system of claim 15, wherein the expandable intraluminalmedical device is disposed within the passageway of the main body. 17.The medical device loading system of claim 16, wherein the expandableintraluminal medical device has a radially-expanded configuration and aradially-compressed configuration; and wherein the expandableintraluminal medical device is disposed within the distal chamber of thepassageway of the main body in the radially-expanded configuration. 18.The medical device loading system of claim 17, wherein the expandableintraluminal medical device includes a biologic component.
 19. A medicaldevice loading system, comprising: a loading apparatus comprising a mainbody having a proximal end defining a proximal opening, a distal enddefining a distal opening, and a passageway extending between theproximal and distal openings, the passageway defining a proximal chamberhaving a first inner diameter, a distal chamber having a second innerdiameter, and a transition chamber disposed between the proximal anddistal chambers, the second inner diameter being greater than the firstinner diameter and the transition chamber having an inner diameter thattransitions along an axial length of the transition chamber from thesecond inner diameter to the first inner diameter; a delivery cathetercomprising an outer tubular member defining a sheath lumen, a dilatorbody disposed within the sheath lumen and defining a dilator lumen, anda distal tip member comprising an elongate cannula and a distal tipbody, the elongate cannula adapted to be slideably disposed within thedilator lumen and the distal tip body defining an outer diameter that issmaller than the second inner diameter and larger than the first innerdiameter; an expandable intraluminal medical device including a biologiccomponent; a proximal cap disposed on the proximal end of the main body,the proximal cap defining a cap passageway in communication with thepassageway of the main body; and at least one pull wire attached to theproximal cap and extending into the passageway of the main body; whereinthe distal tip member has a separable connection that divides the distaltip member into a proximal distal tip member portion and a distal distaltip member portion when disrupted.
 20. A medical device loading system,comprising: a loading apparatus comprising a main body having a proximalend defining a proximal opening, a distal end defining a distal opening,and a passageway extending between the proximal and distal openings, thepassageway defining a proximal chamber having a first inner diameter, adistal chamber having a second inner diameter, and a transition chamberdisposed between the proximal and distal chambers, the second innerdiameter being greater than the first inner diameter and the transitionchamber having an inner diameter that transitions along an axial lengthof the transition chamber from the second inner diameter to the firstinner diameter; a delivery catheter comprising an outer tubular memberdefining a sheath lumen, a dilator body disposed within the sheath lumenand defining a dilator lumen, and a distal tip member comprising anelongate cannula and a distal tip body, the elongate cannula adapted tobe slideably disposed within the dilator lumen and the distal tip bodydefining an outer diameter that is smaller than the second innerdiameter and larger than the first inner diameter; an expandableintraluminal medical device disposed within the passageway of the mainbody, the expandable intraluminal medical device including a biologiccomponent; a proximal cap disposed on the proximal end of the main bodyand sealing the proximal opening; a distal cap disposed on the distalend of the main body and sealing the distal opening; wherein the distaltip body defines a tapered proximal surface and the distal tip memberhas a separable connection on the tapered proximal surface that dividesthe distal tip member into a proximal distal tip member portion and adistal tip member portion when disrupted.